Circuits for storing information



R. w. MOWERY 3,212,066

CIRCUITS FOR STORING INFORMATION Filed Jan. 6, 1964 Oct. 12, 1965 3,212,066 Patented Uct. 12, 1965 ffice 3,212,066 CIRCUITS FOR STORING INFORMATIN Robert W. Mowery, Columbus, Ohio, assigner, by mesne assignments, to United States Steel Corporation, Pittsburgh, Pa., a corporation of New `Iersey Filed Jan. 6, 1964, Ser. No. 335,988 4 Claims. (Cl. 340-173) This invention relates to improved circuits for storing information.

An object of the invention is to provide simplified circuits which store information until it is needed and which reset themselves automatically after the information is used.

A further object is to provide circuits of the foregoing type which are particularly adapted to` classifying and separating articles in a sequence according to some characteristic, for example, prime or or -gradel A further object is to provide improved circuits which store information concerning two or more items and automatically reset after each item has been acted on in response to the stored information.

In the drawing:

FIGURE 1 is a schematic wiring diagram of my circuit arranged =for storing information concerning two items; and

FIGURE 2 is a schematic wiring diagram of my circuit modified for storing information concerning a larger number of items.

FIGURE 1 shows a classification device or other source of information and a responsive device 12. In one example the classification device automatically inspects each article of a sequence for flaws, thereby determining whether the article is prime or off-grade. The responsive device can be a mechanically operated gate which directs prime and off-grade articles along different routes. Nevertheless it .is apparent my invention has broader application, and I do not intend this example to be limiting.

In the form shown in FIGURE 1, my circuit comprises two storage units A and B, a selector 13 connected to the classification device 10, and a reset mechanism 14. Conductors 15a and 15b lead from the selector to unit-s A and B respectively. I connect the coil of a relay 16 to conductor 15a through a conventional amplifier 17. In the example of inspecting articles, the selector activates unit A via conductor 15a and energizes relay 16 as the first article of the sequence arrives at the classification device 10 for inspection. The classification device then transmits a signal to unit A as to whether the first article is prime or off-grade. Unit A stores `this information. Meanwhile the second article arrives at the classification device 10, whereupon the selector activates the other storage unit `B via conductor 15b and deenergiZes relay 16. Before the first article reaches the responsive device 12, unit A sets this device to route the article. After the first article leaves the responsive device, the responsive device is connected to unit B, which acts in like manner for the second article. The cycle continues indefinitely with unit A controlling odd-numbered articles and unit B even-numbered. I have illustrated the selector 13 as a conventional flip-iiop, but I could use other devices capable of transmitting signals through either of several paths, such as a stepping switch or a relay.

In more detail, storage unit A includes a controlled rectifier 13, the gate of which I connect to conductor 15a via a diode 19 and resistor 20. I connect the anode of the controlled rectifier to a positive D.-C. voltage source B-lvia a resistor 21 and connect the cathode to ground via a Zener diode 22. I also connect another resistor 23 between the gate and ground to reference the gate to the cathode. I connect the anode of a second controlled rectifier 24 to the cathode of the first controlled rectifier 18, and connect the cathode of the second controlled rectifier to ground via a resistor 25. Relay 16 has two armatures 26 and 2.7. When the relay is energized, these armatures engage contacts 16a and 16h respectively. When the relay is deenergized, the armatures engage contacts 16C and 16d respectively. I connect the armature 26 to the classification device 10 and connect the contact 16a to the gate of the second controlled rectifier 24. I also connect another resistor 28 between the gate of the second -controlled rectifier and ground to reference the gate to the cathode.

The reset mechanism 14 includes a normally open limit switch 30 which I connect in seriesI with the coil of a second relay 31. The limit switch is physically located in the responsive device 12 and momentarily closes and energiZes relay `31 each time the responsive device acts, that is, each time an article travels therethrough. Relay 31 has two normally open contacts 31a and 31b. I connect contact 31a between armature 27 of relay 16 and ground. I connect contact 31b to a second selector 32, again illustrated as a conventional ip-fiop. I connect the output conductor from the iii-pflop to the coil of a third relay 33 through a conventional amplifier 34. Relay 33 has an armature 35 which engages a contact 33a when the relay is energized and which engages another contact 33h when the relay is deenergized. I connect the cathode of the second controlled rectifier 24 to the contact 33a and connect the armature 35 of relay 33 to the responsive device 12.

A controlled rectifier normally is nonconductive, but becomes conductive when a positive pulse is applied to its gate. lf there .is a positive voltage on its anode when the rectifier becomes conductive, current flows from anode to cathode. The rectifier remains conductive and current continues t-o flow until the voltage source is removed, even though the pulse on its gate terminates. The Zener diode 22 in -my circuit assures a minimum anode voltage for the controlled rectifier 24. When current passes through the Zener diode, there is a Voltage drop equal to its Zener Voltage, but the drop is substantially constant regardless of the magnitude of current.

When the selector 13 activates the storage unit A, conductor 15a carries a positive pulse to the gate of the tirst controlled rectifier 18. The B+ voltage already is applied to the anode of this rectifier; hence the rectifier commences to conduct. A voltage appears across the Zener diode 22 equal to its Zener voltage. This voltage also is applied to the anode of the second controlled rectifier 24. At this stage the gate of the second controlled rectifier 24 is connected to the classification device 10 via the armature 26 and Contact 16a, since relay 16 is energized when unit A is activated. If the article in the classification device 10 is of one class (for example offgrade), the classification device transmits a pulse to the `gate of the second controlled rectifier 24, whereupon current commences to flow therethrough. If the article is of the other class (for example prime), no pulse is transmitted and no current flows through the second controlled rectifier 24. In either instance the information represented by the existence or non-existence of current fiow through the second controlled rectifier 24 is stored until used, as hereinafter explained.

When an article momentarily closes the limit switch 3f) and energizes relay 31, its contacts 31h momentarily close and thus transmit a signal to the fiip-op 32. If the flipflop is transmitting a voltage which causes amplifier 34 to energize relay 33, the signal to the flip-flop turns off this voltage and relay 33 is deenergized. If the flip-flop is not transmitting such a voltage, the signal turns on this voltage and relay 33 is energized. I arrange the operating sequence so that relay 33 is energized when even-numbered articles close the limit switch 30 and deenergized when odd-numbered articles close the switch. Hence sometime while the storage unit A is activated, armature 35 of the relay engages contact 33a to connect the cathode of the second controlled rectifier 24 to the responsive device 12. If current is flowing through this controlled rectifier, this connection carries a voltage signal to the responsive device; otherwise there is no signal. The responsive device utilizes the presence or absence of a signal to set itself for proper routing of the article.

Meanwhile the second article has arrived at the classification device 10, storage unit B has been activated, and relay 16 deenergized. Unit A retained its setting, since termination of the signals on the gates of its controlled rectifiers 18 and 24 has no effect, as already explained. Armature 26 of relay 16 engages contact 16C to enable the storage unit B to receive a signal concerning the second article. Unit B is similar in construction and operation to unit A; hence I have not repeated the description. Armature 27 of relay 16 engages contact 16d. When relay 31 is energized momentarily as the first article leaves the responsive device 12, closing of its contact 31a connects resistor 21 to ground through contact 16d, armature 27 and contact 31a. The first controlled rectifier 18 momentarily is short-circuited, and the voltage 'on its anode effectively removed, whereupon current ceases to fiow therethrough. If current is flowing through the second controlled rectifier 24, termination of the current through the first also removes the voltage from the second. Thus the storage unit A is reset and ready to be activated when the third article arrives at the classification device 10.

FIGURE 2 shows a modification which enables my invention to be utilized for storing information concerning a larger number of articles. The classification device 10, responsive device 12 and the individual storage units A, B N are similar in construction and operation to those in FIGURE l; hence I have not repeated the showing. The modified circuit utilizes as a selector a stepping switch 4t) which has two arms 41 and 42 connected to the classification device 10. Arm 41 can engage any one of a series of contacts 41a, 4111 41n to which I connect conductors a, 15b 1511 leading to the first controlled rectier of the respective storage units. Arm 42 engages the corresponding contact of a series 42a, 4211 42n, which I connect to the second controlled rectifier of the respective units. I mechanically connect a limit switch 43 to the classification device 10. As each article arrives, the limit switch closes momentarily and advances the arms of the stepping switch 40 to the next contacts, as known in the art.

The reset mechanism 14a includes a limit switch 30 and relay 31 similar to FIGURE 1. As a second selector, the modified circuit utilizes another stepping switch 44 which has two arms 45 and 46 connected to the responsive device 12 and contact 31a respectively. Arm 4S can engage any one of a series of contacts 45a, 45b 45n to which I connect the cathodes of the second controlled rectifier of the respective storage units. Arm 46 engages the preceding contact of a series 46a, 4Gb 46n to which I connect the short-circuiting conductors from the respective storage units. Each time the limit switch 30 closes, arm 45 moves to the next contact to connect the responsive device 12 to the next storage unit. Arm 46 moves to the contact corresponding to the contact which arm 45 disengages to cancel the preceding storage and thus reset the unit.

From the foregoing description, it is seen that my invention affords simplified improved circuits for storing information until needed, and automatically resetting themselves after the information has been used. In its simplest form shown in FIGURE l, the circuit stores information concerning two items, one of which can be undergoing classification while the other is being routed in accordance with a previous classification. Nevertheless, as shown in FIGURE 2, the number of items can be expanded indefinitely.

While I have shown and described certain preferred embodiments of my invention, it is apparent that other modifications may arise. Therefore, I do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

I claim:

1. The combination, with a classification device and a responsive device adapted to act successively on each item of a sequence, of a circuit for storing information obtained in said classification device to control subsequent action of said responsive device, said circuit comprising a plurality of storage units, each of which units includes respective interconnected first and second controlled rectifiers, said circuits also comprising a selector connected t0 said classification device and to the first controlled rectifier of each unit to activate each unit in turn by making conductive the first controlled rectifier thereof as different items are classified, additional means connecting said classification device to the second controlled rectifier of each unit for transmitting information to the activated unit concerning the item undergoing classification by making conductive the second controlled rectifier thereof in response to a predetermined type of information concerning an item, means selectively connecting each of said units to said response device for transmitting stored information thereto when the responsive device acts on the item to which the information relates, and means for resetting said units after said responsive device uses the information stored therein.

2. A combination as defined in claim 1 in which the means connecting said units to said responsive device is connected to the second controlled rectifier of each unit, and in which said resetting means short-circuits said first controlled rectifier.

3. A combination as defined in claim 1 in which each of said controlled rectifiers has an anode, a cathode and a gate, and each of said units also includes a voltage source connected to the anode of said first controlled rectifier, the anode of said second controlled rectifier being connected to the cathode of the first, the gate of said first controlled rectifier being connected to said selector to start current flow through the first controlled rectifier and apply a voltage to the second when the unit is activated, said additional means being connected to the gate of said second controlled rectifier to start current flow therethrough in response to predetermined characteristics of an item.

4. A combination as defined in claim 3 in which said means for resetting said units includes a limit switch operated by each item routed from said responsive device, and a short circuit for said first controlled rectifier completed when said limit switch operates.

References Cited by the Examiner UNITED STATES PATENTS 2,952,839 9/60 Capanna 340-173 IRVING L. SRAGOW, Primary Examiner. 

1. THE COMBINATION, WITH A CLASSIFICATION DEVICE AND A RESPONSIVE DEVICE ADAPTED TO ACT SUCCESSIVELY ON EACH ITEM OF A SEQUENCE, OF A CIRCUIT FOR STORING INFORMATION OBTAINED IN SAID CLASSIFICATION DEVICE TO CONTROL SUBSEQUENT ACTION OF SAID RESPONSIVE DEVICE, SAID CIRCUIT COMPRISING A PLURALITY OF STORAGE UNITS, EACH OF WHICH UNITS INCLUDES RESPECTIVE INTERCONNECTED FIRST AND SECOND CONTROLLED RECTIFIERS, SAID CIRCUITS ALSO COMPRISING A SELECTOR CONNECTED TO SAID CLASSIFICATION DEVICE AND TO FIRST CONTROLLED RECTIFIER OF EACH UNIT TO ACTIVATE EACH UNIT IN TURN BY MAKING CONDUCTIVE THE FIRST CONTROLLED RECTIFIER THEREOF AS DIFFERENT ITEMS ARE CLASSIFIED, ADDITIONAL MEANS CONNECTING SAID CLASSIFICATION DEVICE TO THE SECOND CONTROLLED RECTIFIER OF EACH UNIT FOR TRANSMITTING INFORMATION TO THE ACTIVATED UNIT CONCERNING THE ITEM UNDERGOING CLASSIFICATION BY MAKING CONDUCTIVE THE SECOND CONTROLLED RECTIFIER THEREOF IN RESPONSE TO A PREDETERMINED TYPE OF INFORMATION CONCERNING AN ITEM, MEANS SELECTIVELY CONNECTING EACH OF SAID UNITS TO SAID RESPONSE DEVICE FOR TRANSMITTING STORED INFORMATION THERETO WHEN THE RESPONSIVE DEVICE ACTS ON THE ITEM TO WHICH THE INFORMATION RELATES, AND MEANS FOR RESETTING SAID UNITS AFTER SAID RESPONSIVE DEVICE USES THE INFORMATION STORED THEREIN. 